When teeth are whitened, restorations such as bonding, dental crowns or porcelain veneers are not affected by bleach and usually maintain their default color while the surrounding teeth are whitened. This results in what is frequently called "technicolor teeth." This can also occur when whitening strips or tray do not cover all the teeth and only do partial whitening. Technicolor teeth can result from either in-office or at-home processes; such as too-short whitening strips that fail to cover an adequate span of teeth.